Category Archives: Tech Tips

Tech Tips: My $350 coat leaks!

Here comes the storm… is your rain-jacket ready? Chief Lake from the John Muir Trail. copyright Colby J Brokvist

This happens all the time to expensive waterproof jackets, but no worries; the jacket is most likely fine. It just needs some love. Let’s begin with a little background regarding waterproof-breathable (W-B) fabrics. These products (such as Gore-tex) are a plastic layer or laminate embedded within the nylon fabric of your shell. Additionally, the outer layer of nylon the shell is treated with a Durable Water Repellant (DWR) coating to shed water off the nylon.

This outer DWR coating is the key to the “leaking” issue. If the DWR wears off the outer nylon, the nylon wets out. The W-B layer still prevents the water from soaking through to you. However, with the outer nylon saturated, the W-B cannot “breathe” properly because the moisture you are creating as you move cannot escape. So, any moisture you create becomes trapped inside your jacket and you become wet. This all gives the appearance that your jacket is leaking. After all, it’s wet on the outside and wet on the inside in the same places!

So, the issue is not that your jacket leaks, but that the DWR has worn off and the jacket cannot function properly. This is not a quality problem with your jacket.  As you use your jacket and stuff it in and out of your pack, the DWR coating is abraded and wears off. This is normal. Periodically, re-treat it with an after market spray such as Revivetech. The spray-on stuff is best (wash-in is the alternative). A simple spray once or twice a season will keep your jacket in good working order, with no more apparent “leaking problems”. Every other season or so, it’s also a good idea to throw your jacket in the dryer on medium heat. This will warm the W-B layer and it will “even out” the surface so that the jacket continues to breathe well.

A rainy day is no excuse to not have fun in the backcountry. So grab your rain-jacket and hit the trail!

Tech Tips: Down vs Synthetic

SYMG Guides Colby and Laura wearing Columbia's Ultrachange synthetic jackets on a damp and snowy day in Yosemite Valley

One questions we get a lot in the SYMG office is regarding down vs synthetic insulation. These are fill choices for all of the sleeping bag and “puffy” jackets. Let’s explore the differences of each and discuss situations where each one excels.

Down fill is very light and compressible. It is typically given a “fill” rating between 500 and 900, indicating the quality of the down. The higher the number the lighter, more compressible and more expensive the piece will be. For any given temperature rating, down is lighter and more compressible than a synthetic fill. It also has a longer lifespan. The major drawback of down is that if it gets wet, it is utterly useless and takes a very long time to dry, even in ideal conditions. A waterproof dry-sack will keep your bag dry even when dunked in a creek, but humidity is more difficult to contend with, and accidents do happen.

Synthetic fills are man-made hollow fibers that trap heat. Their major benefits are that they retain up to 60% of their warmth even when wet and are less expensive than down for any given temperature rating. The downside is that they are heavier and less compressible than down.

So, which to use? I like to think of my gear choices in terms of a system.  In this case, we want our system to be lightweight, take up a minimum volume in our pack, and we need insulative value even in the event that our gear gets wet. Packing a synthetic bag and jacket will certainly keep us warmer if wet, but will be heavier than we’d like. All down runs the risk of having no insulating pieces if it gets wet. So, the combination that works best is perhaps a down sleeping bag and synthetic jacket. Since the bag is heavier and bulkier than the jacket by nature, it’s a good candidate for down. Meanwhile, the synthetic jacket will work if the down bag gets wet.

Especially in the sunny Sierra, this system works great. However, there are times when other systems are preferable. For instance, on kayaking trips or backpacking in rainy, wet forests of Olympic National Park, you may prefer to have all synthetics since there is a good chance of getting your stuff wet. On winter mountaineering trips, all down might be best because there’s little chance of getting them wet (everything is frozen). This minimizes weight and space, making room for all the extra winter gear.